How to know a used GPU has been used for crypto mining

You can also be interested in these:

If you are thinking of buying a used GPU, you may be concerned about its history. In this article, we will provide you with information on how to know if the GPU you plan to buy has been used for Ethereum mining.

There is nothing wrong with a GPU being used for cryptocurrency mining, as long as it has been well-cooled and well-maintained. It’s also important to know for how long it was used for this purpose, as it’s not the same thing as 6 months or 2 years.

Why are used GPUs for mining being sold in bulk?

Ethereum changed the way it works in September 2021, which led to a massive sale of used GPUs for mining. Up until that point, all transactions and blocks were validated through a process called “proof of work” or PoW, which required a lot of computational power to perform complex mathematical calculations. With Ethereum Merge, the process has become much simpler, as it has switched to a “proof of stake” or PoS, which requires much less computational power. Now, the essential thing is to own 32 ETH to be a validating node, although power is still required, but has decreased by 99%.

The use of GPUs in the mining process is no longer as necessary or at least not on a large scale. Powerful systems are still required to carry out the verifications, but a large number of GPUs is not necessary.

What happens to the GPUs when they are no longer needed? Approximately 45% of the previous Ethereum network’s power was transferred to other networks like Ravencoin, Grin, and others that are compatible with GPUs. The remaining 55% disappeared, meaning the miners shut down and the hardware was sold. This results in a massive sale of GPUs that come from mining. Now, it’s important to know how to identify them, which is easier than it seems.

How to identify a graphics card used in mining

Let’s see what factors can indicate to us whether a graphics card has been used in mining. We will explain to you from the simplest identification to different methods to detect it in case of doubt.

A seller with many graphics cards

The first thing we must do is check the seller’s profile on online platforms, second-hand shops or any other website you visit for the purchase. It is important to see the items they are selling and the ones they have already sold. If they have many graphics cards for sale, they were probably used in Ethereum mining. In addition, we can check if they are selling high-power power supplies or specific motherboards for the mining process.

They do not always have to come from mining. It could be a user who is dedicated to the purchase and sale of second-hand hardware or a retail store. They could even be refurbished or repaired graphics cards. In these cases, it is important to make sure that a minimum six-month warranty is provided and to verify the purchase.

There are several indicators that can reveal those who sell used graphics cards, one of them is the lack of real images of the product. Often, sellers use generic images or images taken from different websites, so it is important to verify and request own images of the product to evaluate its condition.

Specifications are very important

Before making any purchase, it is crucial to know the specifications of the graphics card, especially the amount of VRAM memory. Although this may seem like a trivial detail, it is a crucial technical factor. For example, Ethereum mining requires that the graphics card have at least 6 GB of VRAM memory due to the DAG file that weighs more than 4 GB. If the graphics card does not have enough VRAM memory, it will not be suitable for mining. This does not mean that it has not been used for mining on other blockchain networks with smaller DAGs, but it is not the most common.

It is also important to know if the graphics card has security measures against mining. For example, many of the NVIDIA RTX 30 Series include LHR (Low Hash Rate), a measure that identifies if the GPU is being used for mining and reduces its performance by half. However, this measure has been circumvented on many occasions, so it is not a guarantee. It is important to keep in mind that AMD has never included anti-mining measures in its Radeon products.

It is crucial to know the specific model to verify its working frequencies and other parameters such as working voltages. The latter can be more difficult to find, but a search on the internet can help.

Does the seller keep the box?

Although it may seem like a trivial detail, the lack of a box is an important indicator. If the former owner was a small miner, it is possible that they kept the box, but if they had a mining farm, it is likely that they discarded it. Boxes take up a lot of space and can be uncomfortable, so they are often discarded. If graphics cards are sold second-hand without a box, it is an indication that they may have been used for mining.

Price variations

In the second-hand market, there are two common prices for graphics cards used in mining. Some sellers sell them at prices well above average, while others sell them at much lower prices.

In the first case, the sellers claim that the GPU is for personal use and has barely been used, which is clearly false. It’s a deceptive technique and it’s important to be cautious with these sellers. A high price doesn’t guarantee a good condition.

In the second case, the sellers explicitly mention that the GPU has been used for mining and that its price is lower for that reason. Some provide no justification. If a GPU has a notably lower price than the average market price for the desired model, skepticism is necessary. The key is to compare with the average market price in the second-hand market.

Check the GPU’s condition

The first thing to observe is discolorations on the PCB. If visible defects are identified, it’s likely that the GPU has suffered heat damage due to prolonged intense loads, which is common in graphics used in mining.

External review of the GPU

One aspect to review is the video connection ports. Graphics cards designed or optimized for mining often have fewer HDMI, DP or DVI ports than common ones. Another thing to consider is overclocking: although some miners do not overclock their GPUs to extract cryptocurrencies, others do, so it’s important to check if the DRAM chips have discolorations on the PCB or if there are oily glimmers around them, which would indicate a problem.

The next review requires disassembling the heat sink and evaluating the GPU’s thermal paste. If it’s dry and hardened, it has likely suffered from excessive thermal load, which could generate similar problems as mentioned previously.

BIOS examination and testing

Graphics cards used for mining often have BIOS configurations different from the factory or modified ones. Therefore, you can ask the seller for a GPU-Z screenshot and compare it with the original GPU’s screenshot, which you can probably find easily on the internet. If the values are modified, it’s likely that the graphics card has been overclocked and used for mining.